In the 3rd Generation Partnership Project (3GPP), a radio access method and a radio network for cellular mobile communications (hereinafter, referred to as “Long Term Evolution (LTE),” or “Evolved Universal Terrestrial Radio Access (EUTRA)”) have been considered (NPL 1, NPL 2, NPL 3, NPL 4, and NPL 5). In LTE, a base station device is also referred to as an evolved NodeB (eNodeB), and a terminal device is also referred to as a User Equipment (UE). LTE is a cellular communication system in which an area is divided into a plurality of cells to form a cellular pattern, each of the cells being served by a base station device. A single base station device may manage a plurality of cells.
LTE supports a Time Division Duplex (TDD). LTE that employs a TDD scheme is also referred to as TD-LTE or LTE TDD. In TDD, uplink signals and downlink signals are time-division multiplexed. LTE supports a Frequency Division Duplex (FDD).
In 3GPP, Carrier Aggregation is specified such that a terminal device is capable of simultaneously performing transmission and/or reception on five serving cells (component carriers) at most.
Further, in the 3GPP, a configuration, in which a terminal device simultaneously performs transmission and/or reception on more than five serving cells (component carriers), is studied. Furthermore, a configuration, in which a terminal device performs transmission of a physical uplink control channel on a secondary cell that is a serving cell different from a primary cell, is studied (NPL 6).